The present invention relates to a technical field of a liquid crystal display (LCD) apparatus, LCD panel, LCD array substrate and driving method using the same, and more particularly to a thin film transistor (TFT) LCD apparatus, TFT-LCD panel, TFT-LCD array substrate and driving method using the same.
Conventionally, a manufacturing cost reduction is a critical issue of the LCD's manufacturing procedure. A data line sharing (DLS) mechanism is commonly used wherein the number of gate lines is doubled and the number of data lines is halved to diminish the amount of source driver for thus lowering the costs.
Regarding a driving method of conventional LCD panel, since the switch frequency of the data line polarity using a column inversion is lower, the power consumption of the driving manner is reduced and widely used. FIG. 1 is a schematic view of a TFT-LCD with a data line sharing (DLS) mechanism and column inversion in the prior art. G_1 to G_8 represent the serial numbers of the gate lines and D_1 to G_5 represent the serial numbers of the data lines. Each region enclosed by a dashed line is defined as a sub-pixel wherein the positive and negative signs in the sub-pixels represent the polarities of the driving voltage. The sub-pixel polarity of one data line in a column is opposite the sub-pixel polarity in the left or right data line related the one data line, which is defined as a column inversion manner.
FIG. 1 is a conventional red-green-blue (RGB) structure. When the RGB structure is operated with the DLS mechanism, the electrical potential of common electrode E_cm will drift in some color mixing frames, e.g. cyan color frame formed by green and blue colors, thereby causing poor display quality, e.g. crosstalk, since the capacitor coupling is formed by liquid crystal capacitance and storage capacitance between sub-pixel electrode E_pixel and common electrode E_cm. FIG. 2a is a schematic signal waveform of the data lines in FIG. 1 when the display panel is in a color-mixing status. In a cyan color frame formed by green and blue colors, the level of common electrode E_cm is 7V (voltage) wherein the positive polarity voltage of the gray level L255 is 14V and the negative polarity voltage is 0V. In FIGS. 1 and 2, data line D_2 is composed of green sub-pixels G and blue sub-pixels B in a direct current signal waveform with a negative polarity voltage 0V. The data line D_3 has positive polarity wherein when the odd data lines are switched on, the voltage written into the red sub-pixel is common voltage 7V and the even data lines are switched on, the voltage written into the green sub-pixel is 14V. In the data line D_4, when the odd data lines are switched on, the voltage written into the blue sub-pixel is 0V and the even data lines are switched on, the voltage written into the red sub-pixel is common voltage 7V. However, the waveform of data lines D_3 and D_4 from low level to high level or vice versa are similar, as shown in dashed line regions. In this case, when the data signal is written to the sub-pixel electrode E_pixel, the liquid crystal capacitor C_lc and storage capacitor C_st related to the common electrode E_cm generates a coupling capacitance therebetween so that electrical potential of the common electrode E_cm is drifted. In FIG. 2a, when the signal levels in data lines D_3 and D_4 are changed from low to high, the common voltage in the whole column sub-pixels pulls high. On the contrary, when the signal levels in data lines D_3 and D_4 are changed from high to low, the common voltage in the whole column sub-pixels pulls low. Thus, the changed common voltage is unstable, which may downgrade the display quality due to crosstalk effect. As shown in FIG. 2b, when a white display region 200 is added to a color-mixing background region, the brightness of the background regions 201 in the lateral sides of the white display region 200 is different from the brightness in the region 202.
FIG. 3 is a schematic view of a conventional display panel with white, red, green and blue (WRGB) sub-pixels. When the WRGB display panel shown a pure color, FIG. 3 has the same problem as FIG. 2b, thereby causing crosstalk. As shown FIG. 4, when a white display region 400 is added to a color-mixing background region, the brightness of the background regions 401 in the lateral sides of the white display region 200 is different from the brightness in the region 402.